DYSTONIA

Dystonia a neurological condition where muscles contract involuntarily. It can occur anywhere in the body, including the muscles of the arms, legs, trunk, or face, and appears as repetitive, twisting movements and unnatural posture. Nearly half of patients with MSA experience dystonia. Dystonia in MSA predominantly affects the head and neck area in a form called antecollis, which accounts for one-quarter of all dystonia in MSA patients, with dystonia in one limb being present in over 20% of patients studied. Both of these types of dystonia, when present, can affect balance and walking in MSA patients. Dystonia can also affect the face and mouth, affecting speech. If dystonia affects the vocal cords, obstructive sleep apnea can result.

1. Non-pharmacologic treatment of dystonia in MSA include:

• Speech therapy can be beneficial for patients whose dystonia affects their speech. Speech therapy has been shown to be a very effective treatment option in patients with Parkinson’s Disease, and may be especially effective as patients with MSA have more trouble with speech than those with Parkinson’s Disease.
  
  
• Physical and occupational therapy can assist patients with dystonia. Physical therapy helps to maintain mobility and to reduce the risk of contracture, spasm and further loss of function. Occupational therapy has been shown to minimize the risk of fall, assist patients in completing their activities of daily living with the use of assistive devices or modifications around the home.
• Geste antagoniste is a sensory ‘trick’ that involves moving an arm to the face or head to alleviate abnormal posture associated with cervical dystonia. This maneuver has proven quite effective at reduction in head deviation in patients with cervical dystonia.
• Electromyographic (EMG) biofeedback has been found to be an effective therapeutic technique for decreasing decrease dystonia in patients with movement disorders.
• Continuous positive airway pressure devices can be used when dystonia affects vocal cords and breathing, resulting in sleep apnea.
• In refractory cases of dystonia, surgical intervention can be considered. Surgical interventions can either be focused on the brain or peripherally, but the goal for both is to interrupt the communication between nerve and muscle that causes the involuntary contraction seen in dystonia.

2. Pharmacologic treatment of dystonia in MSA include:

• Botulinum toxin has been found to relieve many types of focal dystonias and is widely used in MSA. Localized injections, especially for facial and cervical dystonias, have proven effective.
• The symptoms of dystonia can also be treated with anticholinergic medications, blocking the muscle-contracting effect of acetylcholine. Drugs in this class include benztropine, biperiden, procyclidine, and scopolamine.
• Drugs that cause muscle relaxation have also been used in treating dystonia in MSA. These include those that increase levels of the neurotransmitter gamma-aminobutyric acid (GABA) which has the effect of reducing activity of the neurons it binds to, thereby causing muscle relaxing effect (e.g. baclofen, benzodiazepines and zolpidem) as well as traditional muscle relaxants, such as carisoprodol, cyclobenzaprine, metaxalone and methocarbamol. These medications must be used with caution, as dependency is a side effect of some.

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